/* ================================
   AI Programming Tools Handbook
   Design System & Component Styles
   Professional Tech Documentation Theme
   ================================ */

/* ========== CSS CUSTOM PROPERTIES ========== */
:root {
  /* Color Palette - Tech Professional */
  --color-primary: #1E40AF;
  --color-primary-light: #3B82F6;
  --color-primary-dark: #1E3A8A;
  --color-secondary: #06B6D4;
  --color-secondary-light: #22D3EE;
  --color-secondary-dark: #0891B2;
  --color-accent: #9333EA;
  --color-accent-light: #A855F7;
  --color-accent-dark: #7C3AED;

  /* Status Colors */
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-error: #EF4444;
  --color-info: #3B82F6;

  /* Background Colors */
  --color-bg-dark: #0A0F1C;
  --color-bg-dark-alt: #111827;
  --color-bg-dark-elevated: #1F2937;
  --color-bg-light: #FFFFFF;
  --color-bg-light-alt: #F8FAFC;
  --color-bg-light-elevated: #F1F5F9;

  /* Text Colors */
  --color-text-dark: #F8FAFC;
  --color-text-dark-secondary: #94A3B8;
  --color-text-dark-muted: #64748B;
  --color-text-light: #0F172A;
  --color-text-light-secondary: #475569;
  --color-text-light-muted: #64748B;

  /* Border & Divider Colors */
  --color-border-dark: rgba(255, 255, 255, 0.08);
  --color-border-dark-strong: rgba(255, 255, 255, 0.15);
  --color-border-light: rgba(15, 23, 42, 0.08);
  --color-border-light-strong: rgba(15, 23, 42, 0.15);

  /* Typography */
  --font-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;

  /* Font Sizes - Mobile First */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;

  /* Spacing System */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  --spacing-3xl: 6rem;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;

  /* Glassmorphism Effects */
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-bg-strong: rgba(255, 255, 255, 0.1);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-border-strong: rgba(255, 255, 255, 0.2);
  --glass-blur: 16px;
  --glass-blur-strong: 24px;

  /* Premium Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  --shadow-glow-primary: 0 0 20px rgba(59, 130, 246, 0.3);
  --shadow-glow-secondary: 0 0 20px rgba(6, 182, 212, 0.3);
  --shadow-glow-accent: 0 0 20px rgba(147, 51, 234, 0.3);
  --shadow-inner: inset 0 2px 4px 0 rgba(0, 0, 0, 0.1);

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 400ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Z-Index Scale */
  --z-base: 1;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal: 400;
  --z-popover: 500;
  --z-tooltip: 600;
}

/* ========== DARK MODE OVERRIDES ========== */
[data-theme="dark"] {
  --color-bg: var(--color-bg-dark);
  --color-bg-alt: var(--color-bg-dark-alt);
  --color-bg-elevated: var(--color-bg-dark-elevated);
  --color-text: var(--color-text-dark);
  --color-text-secondary: var(--color-text-dark-secondary);
  --color-text-muted: var(--color-text-dark-muted);
  --color-border: var(--color-border-dark);
  --color-border-strong: var(--color-border-dark-strong);
}

[data-theme="light"] {
  --color-bg: var(--color-bg-light);
  --color-bg-alt: var(--color-bg-light-alt);
  --color-bg-elevated: var(--color-bg-light-elevated);
  --color-text: var(--color-text-light);
  --color-text-secondary: var(--color-text-light-secondary);
  --color-text-muted: var(--color-text-light-muted);
  --color-border: var(--color-border-light);
  --color-border-strong: var(--color-border-light-strong);

  /* Light mode glass adjustments */
  --glass-bg: rgba(255, 255, 255, 0.8);
  --glass-bg-strong: rgba(255, 255, 255, 0.9);
  --glass-border: rgba(0, 0, 0, 0.08);
  --glass-border-strong: rgba(0, 0, 0, 0.12);
}

/* ========== RESET & BASE STYLES ========== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: 400;
  line-height: 1.7;
  letter-spacing: -0.01em;
  color: var(--color-text);
  background-color: var(--color-bg);
  transition: background-color var(--transition-base), color var(--transition-base);
  overflow-x: hidden;
  min-height: 100vh;
}

/* Respect user's motion preferences */
@media (prefers-reduced-motion: reduce) {

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ========== TYPOGRAPHY ========== */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.025em;
  color: var(--color-text);
  margin-bottom: var(--spacing-md);
}

h1 {
  font-size: var(--text-4xl);
  font-weight: 800;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-accent) 50%, var(--color-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  background-size: 200% 200%;
  animation: gradientShift 8s ease infinite;
}

@keyframes gradientShift {

  0%,
  100% {
    background-position: 0% 50%;
  }

  50% {
    background-position: 100% 50%;
  }
}

h2 {
  font-size: var(--text-3xl);
  font-weight: 700;
  letter-spacing: -0.02em;
}

h3 {
  font-size: var(--text-2xl);
  font-weight: 600;
}

h4 {
  font-size: var(--text-xl);
  font-weight: 600;
}

h5 {
  font-size: var(--text-lg);
  font-weight: 600;
}

h6 {
  font-size: var(--text-base);
  font-weight: 600;
}

p {
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-secondary);
}

a {
  color: var(--color-secondary);
  text-decoration: none;
  transition: color var(--transition-fast), text-decoration-color var(--transition-fast);
  text-decoration: underline;
  text-decoration-color: transparent;
  text-underline-offset: 3px;
}

a:hover {
  color: var(--color-secondary-light);
  text-decoration-color: var(--color-secondary-light);
}

a:focus-visible {
  outline: 2px solid var(--color-secondary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* ========== LAYOUT COMPONENTS ========== */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--spacing-sm);
}

@media (min-width: 768px) {
  .container {
    padding: 0 var(--spacing-lg);
  }
}

@media (min-width: 1024px) {
  .container {
    padding: 0 var(--spacing-xl);
  }
}

/* ========== DOCS LAYOUT (Sidebar + Content) ========== */
.docs-layout {
  display: flex;
  min-height: 100vh;
  padding-top: 64px;
}

/* Sidebar */
.sidebar {
  position: fixed;
  top: 64px;
  left: 0;
  width: 280px;
  height: calc(100vh - 64px);
  background: var(--color-bg-alt);
  border-right: 1px solid var(--color-border);
  overflow-y: auto;
  overflow-x: hidden;
  padding: var(--spacing-lg) 0;
  z-index: var(--z-sticky);
  transform: translateX(-100%);
  transition: transform var(--transition-smooth), box-shadow var(--transition-base);
  scrollbar-width: thin;
  scrollbar-color: var(--glass-border) transparent;
}

.sidebar::-webkit-scrollbar {
  width: 6px;
}

.sidebar::-webkit-scrollbar-track {
  background: transparent;
}

.sidebar::-webkit-scrollbar-thumb {
  background: var(--glass-border);
  border-radius: var(--radius-full);
}

.sidebar::-webkit-scrollbar-thumb:hover {
  background: var(--glass-border-strong);
}

.sidebar.open {
  transform: translateX(0);
  box-shadow: var(--shadow-2xl);
}

@media (min-width: 1024px) {
  .sidebar {
    transform: translateX(0);
    box-shadow: none;
  }
}

.sidebar__section {
  margin-bottom: var(--spacing-lg);
}

.sidebar__title {
  font-family: var(--font-heading);
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--color-text-muted);
  padding: var(--spacing-xs) var(--spacing-lg);
  margin-bottom: var(--spacing-xs);
}

.sidebar__nav {
  list-style: none;
}

.sidebar__link {
  display: block;
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  padding: 10px var(--spacing-lg);
  border-left: 3px solid transparent;
  transition: all var(--transition-fast);
  cursor: pointer;
  position: relative;
}

.sidebar__link::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 0;
  background: linear-gradient(90deg, rgba(6, 182, 212, 0.1), transparent);
  transition: width var(--transition-fast);
}

.sidebar__link:hover {
  color: var(--color-text);
  border-left-color: var(--color-border-strong);
}

.sidebar__link:hover::before {
  width: 100%;
}

.sidebar__link.active {
  color: var(--color-secondary);
  font-weight: 600;
  border-left-color: var(--color-secondary);
  background: linear-gradient(90deg, rgba(6, 182, 212, 0.15), transparent);
}

.sidebar__sublink {
  display: block;
  font-size: 13px;
  font-weight: 400;
  color: var(--color-text-muted);
  padding: 8px var(--spacing-lg) 8px calc(var(--spacing-lg) + 16px);
  transition: all var(--transition-fast);
  cursor: pointer;
  position: relative;
}

.sidebar__sublink::before {
  content: '';
  position: absolute;
  left: 32px;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 4px;
  border-radius: var(--radius-full);
  background: var(--color-text-muted);
  opacity: 0.4;
  transition: all var(--transition-fast);
}

.sidebar__sublink:hover {
  color: var(--color-text);
  padding-left: calc(var(--spacing-lg) + 20px);
}

.sidebar__sublink:hover::before {
  opacity: 1;
  background: var(--color-secondary);
}

/* Main Content Area */
.main-content {
  flex: 1;
  margin-left: 0;
  padding: var(--spacing-xl) var(--spacing-lg);
  max-width: 100%;
}

@media (min-width: 1024px) {
  .main-content {
    margin-left: 280px;
    max-width: calc(100% - 280px);
    padding: var(--spacing-xl) var(--spacing-2xl);
  }
}

.main-content__inner {
  max-width: 860px;
  margin: 0 auto;
}

/* Mobile sidebar toggle */
.sidebar-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  position: fixed;
  bottom: var(--spacing-lg);
  right: var(--spacing-lg);
  width: 52px;
  height: 52px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: white;
  border: none;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-lg), var(--shadow-glow-primary);
  cursor: pointer;
  z-index: var(--z-fixed);
  transition: all var(--transition-fast);
}

.sidebar-toggle:hover {
  transform: scale(1.1) translateY(-2px);
  box-shadow: var(--shadow-xl), var(--shadow-glow-accent);
}

.sidebar-toggle:active {
  transform: scale(1.05);
}

@media (min-width: 1024px) {
  .sidebar-toggle {
    display: none;
  }
}

/* Sidebar overlay for mobile */
.sidebar-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: calc(var(--z-sticky) - 1);
}

.sidebar-overlay.active {
  display: block;
}

section {
  padding: var(--spacing-2xl) 0;
}

@media (min-width: 768px) {
  section {
    padding: var(--spacing-3xl) 0;
  }
}

/* ========== NAVIGATION ========== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 64px;
  z-index: var(--z-fixed);
  background: var(--glass-bg-strong);
  backdrop-filter: blur(var(--glass-blur-strong));
  -webkit-backdrop-filter: blur(var(--glass-blur-strong));
  border-bottom: 1px solid var(--glass-border);
  transition: all var(--transition-base);
}

.nav__container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) var(--spacing-sm);
  max-width: 1280px;
  margin: 0 auto;
}

.nav__logo {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.nav__logo:hover {
  text-decoration: none;
}

.nav__logo svg {
  flex-shrink: 0;
}

.nav__menu {
  display: none;
  list-style: none;
  gap: var(--spacing-lg);
}

.nav__link {
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.nav__link:hover {
  color: var(--color-text);
  background-color: var(--glass-bg);
}

.nav__toggle {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.nav__hamburger {
  display: flex;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
}

.nav__hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-text);
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
}

.nav__hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(6px, 6px);
}

.nav__hamburger.active span:nth-child(2) {
  opacity: 0;
}

.nav__hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(6px, -6px);
}

/* Mobile Menu */
.nav__menu-mobile {
  position: fixed;
  top: 60px;
  left: 0;
  right: 0;
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
  padding: var(--spacing-md);
  transform: translateY(-100%);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.nav__menu-mobile.active {
  transform: translateY(0);
  opacity: 1;
  visibility: visible;
}

.nav__menu-mobile ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

@media (min-width: 768px) {
  .nav__menu {
    display: flex;
  }

  .nav__hamburger {
    display: none;
  }

  .nav__menu-mobile {
    display: none;
  }
}

/* ========== THEME TOGGLE ========== */
.theme-toggle {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-full);
  padding: var(--spacing-xs);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
}

.theme-toggle:hover {
  background: var(--color-primary);
  transform: scale(1.05);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
  fill: var(--color-text);
}

/* ========== HERO SECTION ========== */
.hero {
  min-height: 60vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: var(--spacing-3xl) var(--spacing-sm);
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg,
      var(--color-bg) 0%,
      var(--color-primary-dark) 50%,
      var(--color-accent) 100%);
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 30% 50%, rgba(59, 130, 246, 0.2), transparent 50%),
    radial-gradient(circle at 70% 50%, rgba(147, 51, 234, 0.2), transparent 50%);
  z-index: 0;
}

.hero__content {
  position: relative;
  z-index: 1;
  max-width: 800px;
}

.hero__title {
  font-size: var(--text-4xl);
  margin-bottom: var(--spacing-md);
  color: var(--color-text-dark);
}

.hero__subtitle {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  color: var(--color-text-dark-secondary);
  margin-bottom: var(--spacing-xl);
}

.hero__cta {
  display: flex;
  gap: var(--spacing-sm);
  justify-content: center;
  flex-wrap: wrap;
}

@media (min-width: 768px) {
  .hero {
    min-height: 80vh;
  }

  .hero__title {
    font-size: var(--text-5xl);
  }

  .hero__subtitle {
    font-size: var(--text-2xl);
  }
}

/* ========== BUTTONS ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: 600;
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-lg);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  min-width: 120px;
  min-height: 44px;
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: transparent;
  color: var(--color-text-dark);
  border: 2px solid var(--color-text-dark);
}

.btn-secondary:hover {
  background: var(--color-text-dark);
  color: var(--color-bg-dark);
}

.btn-ghost {
  background: var(--glass-bg);
  color: var(--color-text);
  border: 1px solid var(--glass-border);
}

.btn-ghost:hover {
  background: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

/* ========== CARDS ========== */
.card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  backdrop-filter: blur(var(--glass-blur));
  transition: all var(--transition-base);
  height: 100%;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
  border-color: var(--color-primary);
}

.card__icon {
  width: 48px;
  height: 48px;
  margin-bottom: var(--spacing-md);
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  border-radius: var(--radius-lg);
  color: white;
}

.card__title {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--spacing-sm);
}

.card__description {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-md);
}

.card__link {
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-secondary);
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
}

/* ========== GRID SYSTEM ========== */
.grid {
  display: grid;
  gap: var(--spacing-lg);
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .grid-2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 768px) {
  .grid-3 {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (min-width: 1024px) {
  .grid {
    gap: var(--spacing-xl);
  }
}

/* ========== CODE BLOCKS ========== */
.code-block {
  position: relative;
  margin: var(--spacing-lg) 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.code-block__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-bottom: none;
  padding: 10px var(--spacing-md);
  position: relative;
}

.code-block__header::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, var(--color-secondary), var(--color-accent), var(--color-primary));
  opacity: 0.5;
}

.code-block__language {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-muted);
  display: flex;
  align-items: center;
  gap: 8px;
}

.code-block__language::before {
  content: '';
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
  background: var(--color-secondary);
  opacity: 0.7;
}

.code-block__copy {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 6px 12px;
  font-family: var(--font-heading);
  font-size: 11px;
  font-weight: 500;
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.code-block__copy:hover {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: white;
  transform: translateY(-1px);
}

pre {
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-top: none;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  padding: var(--spacing-md) var(--spacing-lg);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.7;
  tab-size: 2;
  scrollbar-width: thin;
  scrollbar-color: var(--glass-border) transparent;
}

pre::-webkit-scrollbar {
  height: 6px;
}

pre::-webkit-scrollbar-track {
  background: transparent;
}

pre::-webkit-scrollbar-thumb {
  background: var(--glass-border);
  border-radius: var(--radius-full);
}

code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: rgba(6, 182, 212, 0.1);
  color: var(--color-secondary);
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  font-weight: 500;
}

pre code {
  background: none;
  color: inherit;
  padding: 0;
  font-weight: 400;
}

/* ========== SECTION STYLES ========== */
.section-header {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
}

.section-title {
  font-size: var(--text-3xl);
  margin-bottom: var(--spacing-sm);
}

.section-subtitle {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

@media (min-width: 768px) {
  .section-title {
    font-size: var(--text-4xl);
  }
}

/* ========== FOOTER ========== */
.footer {
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer__content {
  display: grid;
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer__section h4 {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  margin-bottom: var(--spacing-sm);
}

.footer__links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.footer__link {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
}

.footer__link:hover {
  color: var(--color-secondary);
}

.footer__bottom {
  text-align: center;
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
}

@media (min-width: 768px) {
  .footer__content {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ========== ANIMATIONS ========== */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in {
  animation: fadeIn var(--transition-slow) ease-out;
}

/* Intersection Observer animations */
.scroll-reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all var(--transition-slow);
}

.scroll-reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* ========== UTILITY CLASSES ========== */
.text-center {
  text-align: center;
}

.text-gradient {
  background: linear-gradient(135deg, var(--color-primary-light), var(--color-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.mb-sm {
  margin-bottom: var(--spacing-sm);
}

.mb-md {
  margin-bottom: var(--spacing-md);
}

.mb-lg {
  margin-bottom: var(--spacing-lg);
}

.mb-xl {
  margin-bottom: var(--spacing-xl);
}

.mt-sm {
  margin-top: var(--spacing-sm);
}

.mt-md {
  margin-top: var(--spacing-md);
}

.mt-lg {
  margin-top: var(--spacing-lg);
}

.mt-xl {
  margin-top: var(--spacing-xl);
}

.mt-2xl {
  margin-top: var(--spacing-2xl);
}

/* ========== CHAPTER STYLES ========== */
.chapter-section {
  padding: var(--spacing-2xl) 0;
  border-bottom: 1px solid var(--color-border);
  position: relative;
}

.chapter-section:last-child {
  border-bottom: none;
}

.chapter-header {
  margin-bottom: var(--spacing-xl);
  position: relative;
}

.chapter-number {
  display: inline-block;
  font-family: var(--font-heading);
  font-size: 11px;
  font-weight: 700;
  color: var(--color-secondary);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-bottom: var(--spacing-sm);
  padding: 6px 12px;
  background: rgba(6, 182, 212, 0.1);
  border-radius: var(--radius-full);
  border: 1px solid rgba(6, 182, 212, 0.2);
}

.chapter-intro {
  font-family: var(--font-body);
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: var(--spacing-xl);
  max-width: 720px;
}

.content-block {
  margin-bottom: var(--spacing-2xl);
  padding-bottom: var(--spacing-lg);
}

.content-block:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
}

.content-block h2 {
  margin-bottom: var(--spacing-lg);
}

.content-block h3 {
  font-size: var(--text-xl);
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
}

.content-block h4 {
  font-size: var(--text-lg);
  margin-top: var(--spacing-md);
  margin-bottom: var(--spacing-sm);
  color: var(--color-text);
}

/* ========== COMPARISON TABLE ========== */
.comparison-table {
  overflow-x: auto;
  margin: var(--spacing-lg) 0;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.comparison-table table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  font-size: 13px;
  line-height: 1.6;
}

.comparison-table th,
.comparison-table td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--color-border);
  border-right: 1px solid var(--color-border);
}

.comparison-table th:first-child,
.comparison-table td:first-child {
  border-left: 1px solid var(--color-border);
}

.comparison-table th {
  background: var(--color-bg-elevated);
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-secondary);
  position: sticky;
  top: 0;
  z-index: 1;
}

.comparison-table th:first-child {
  border-top-left-radius: var(--radius-lg);
}

.comparison-table th:last-child {
  border-top-right-radius: var(--radius-lg);
}

.comparison-table td {
  background: var(--glass-bg);
  color: var(--color-text-secondary);
  vertical-align: top;
}

.comparison-table td:first-child {
  font-weight: 500;
  color: var(--color-text);
}

.comparison-table tbody tr:nth-child(even) td {
  background: var(--color-bg-alt);
}

.comparison-table tbody tr:last-child td:first-child {
  border-bottom-left-radius: var(--radius-lg);
}

.comparison-table tbody tr:last-child td:last-child {
  border-bottom-right-radius: var(--radius-lg);
}

.comparison-table tbody tr {
  transition: background var(--transition-fast);
}

.comparison-table tbody tr:hover td {
  background: rgba(6, 182, 212, 0.08);
}

/* ========== TOOL BADGES ========== */
.tool-badge {
  display: inline-flex;
  align-items: center;
  padding: 5px 12px;
  border-radius: var(--radius-md);
  font-family: var(--font-heading);
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.15);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.tool-badge:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.tool-badge.cursor {
  background: linear-gradient(135deg, #1E40AF, #3B82F6);
  color: white;
}

.tool-badge.copilot {
  background: linear-gradient(135deg, #6e40c9, #a855f7);
  color: white;
}

.tool-badge.antigravity {
  background: linear-gradient(135deg, #059669, #10b981);
  color: white;
}

/* ========== ALERT BOXES ========== */
.alert-box {
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--radius-lg);
  margin: var(--spacing-lg) 0;
  border-left: 4px solid;
  position: relative;
}

.alert-box h4 {
  font-size: var(--text-base);
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  display: flex;
  align-items: center;
  gap: 8px;
}

.alert-box p {
  margin-bottom: var(--spacing-sm);
  line-height: 1.7;
}

.alert-box.info {
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.08), rgba(59, 130, 246, 0.02));
  border-color: var(--color-primary-light);
}

.alert-box.info h4 {
  color: var(--color-primary-light);
}

.alert-box.success {
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.08), rgba(16, 185, 129, 0.02));
  border-color: var(--color-success);
}

.alert-box.success h4 {
  color: var(--color-success);
}

.alert-box.warning {
  background: linear-gradient(135deg, rgba(245, 158, 11, 0.08), rgba(245, 158, 11, 0.02));
  border-color: var(--color-warning);
}

.alert-box.warning h4 {
  color: var(--color-warning);
}

.alert-box ul {
  margin: var(--spacing-sm) 0 0 var(--spacing-md);
  list-style-type: disc;
}

.alert-box li {
  margin-bottom: 4px;
  color: var(--color-text-secondary);
}

.alert-box .comparison-table {
  margin-top: var(--spacing-md);
}

/* ========== BEST PRACTICES BOX ========== */
.best-practices-box {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  margin: var(--spacing-xl) 0;
}

.best-practices-box h3 {
  margin-bottom: var(--spacing-md);
}

.best-practices-box ul {
  list-style: none;
}

.best-practices-box li {
  padding: var(--spacing-xs) 0;
  color: var(--color-text-secondary);
}

/* ========== TOOL WORKFLOW ========== */
.tool-workflow {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
}

.tool-workflow h4 {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
}

.tool-workflow ol {
  margin-left: var(--spacing-lg);
  color: var(--color-text-secondary);
}

.tool-workflow li {
  padding: var(--spacing-xs) 0;
}

/* ========== SCENARIO ========== */
.scenario-intro {
  background: linear-gradient(135deg, rgba(30, 64, 175, 0.1), rgba(147, 51, 234, 0.1));
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

.scenario-intro ul {
  list-style: none;
  margin-top: var(--spacing-sm);
}

.scenario-intro li {
  padding: var(--spacing-xs) 0;
  color: var(--color-text-secondary);
}

/* ========== CONCLUSION ========== */
.conclusion-grid {
  display: grid;
  gap: var(--spacing-lg);
  grid-template-columns: 1fr;
}

@media (min-width: 768px) {
  .conclusion-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.conclusion-card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
}

.conclusion-card h3 {
  margin-bottom: var(--spacing-xs);
}

.conclusion-card h4 {
  color: var(--color-secondary);
  font-size: var(--text-base);
  margin-bottom: var(--spacing-md);
}

.conclusion-card ul {
  list-style: none;
}

.conclusion-card li {
  padding: var(--spacing-xs) 0;
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
}

/* ========== CHAPTER NAV ========== */
.chapter-nav {
  display: flex;
  justify-content: flex-end;
  padding: var(--spacing-lg) 0;
}

.final-note {
  margin-top: var(--spacing-xl);
  padding: var(--spacing-lg);
  background: var(--glass-bg);
  border-radius: var(--radius-lg);
}

.final-note code {
  margin: 0 var(--spacing-xs);
}

/* ========== COLOR BG SECONDARY ========== */
.color-bg-secondary {
  background: var(--color-bg-alt);
}